A long stator motor such as this, which is also referred to as a linear motor, generally has two or more stator coils. Each stator coil includes a stator iron in which slots are incorporated, and cable windings which run in these slots. In the case of a three-phase motor, the three cable windings for the three phases, and thus the slots which are required for this purpose as well, run offset with respect to one another.
Particularly during starting of a vehicle which is driven by a long stator motor, the magnetic flux to be achieved by the known apparatus in the stator iron is not sufficient in order to achieve the desired vehicle acceleration. This is mainly due to the fact that the cable windings cannot withstand the current level that is required for a sufficiently high magnetic flux. The current level cannot be increased since this would otherwise result in an excessively large thermal load on the stator coil.
On the other hand, the cable cross section cannot be enlarged in order to increase the possible current level since broader slots will make it impossible to arrange the slots for three cable windings, as are required for a three-phase motor. Furthermore, no more suitable materials are known for the stator iron which could allow a greater magnetic flux with the same current level.